Description

Diesel soot emissions adversely affect human health, environment, vegetation, climate change, etc. pressurizing governments to have strict emission standards. This project describes the catalytic control of diesel soot emissions. The performance of perovskite is found most promising over spinel, hydrotalcite, and metal oxides catalysts for soot oxidation. LaCoO3 prepared by co-precipitation shows the best result (oxidizing soot totally at 370 oC) than catalyst prepared by sol-gel and solution combustion synthesis. Potash substituted catalyst is more effective than silver substituted. The optimum K substituted catalyst is found to be La0.9K0.1Co0.9Cu0.1O3. A novel finding of the project is that La0.7K0.3ZnOy does not form perovskite structure and remain as mixed metal oxides. This catalyst shows comparable activity to perovskite and yields the following kinetic expression: Rate = 6.46x10^10.exp(-138.12kJ/RT)(m)gsoot/gcat.s